The purpose of Othello is to portray a tragedy, and the atmosphere parallels this purpose, driven by the emotion of jealousy introduced in this story.
Secondly, the jealousy truly built characterization in this script and unveiled the true personalities of each individual character undergoing this emotion. In certain cases such as Iago and Roderigo, jealousy was a part of who they were and this was evident from the beginning of the play. However, jealousy also unveiled the type of person a specific character was, when the audience believed they had the character all figured out. Othello was initially viewed as a generous, often mistaken Moor, who only truly had love for his wife, despite the disbelief others had in judgment of him. Iago's plan was to entertain thoughts of doubt against Othello towards his wife and causing him to believe that she was having an affair with his lieutenant, Michael Cassio. Othello, being nave and trusting in Iago, faces an uncontrollable jealousy rage that leads him to lose all common sense and judgment. Othello eventually kills his wife, unable to control this "Green-eyed monster- in jealousy, and ultimately regrets his actions. What it evident throughout his entire jealous rage, however, is that Othello was not the calm, gentle, loving person he appeared to be. But rather that he had always lived with this "beast- inside of him, only calmed down due to his status in Venice. This is clear because when he goes on to kill Desdemona, he once again appears to be the sweet, gentle, loving man, not engulfed in jealousy, but still murders his wife. Iago was able to unleash this beast within Othello to go ahead with his evil deeds. This jealousy shows that Othello was only a wild, destructive man, living in a world where he was forced to tame himself.
Lastly, jealousy was what really opened up the different areas of conflict within the play. Every stories need conflict; it creates action and draws the audience into the story, rather than repel them away.